1. Field of the Invention
The present invention relates to a sliding-type portable terminal with a sliding module that slides on a pair of sliding rail modules adapted to slide the housing of the terminal along a curve.
2. Description of the Related Art
In general, a “portable communication apparatus” is an apparatus for wireless communication. Portable communication apparatuses may be classified into various categories according to their appearance, such as bar-type terminals, flip-type terminals, and folder-type terminals. The bar-type terminals have a single housing shaped like a bar. The flip-type terminals have a flip that is rotatably coupled to a bar-shaped housing by a hinge device. The folder-type terminals have a folder which is connected to a single bar-shaped housing by a hinge device in such a manner that the folder can be rotated to fold onto, or unfold from, the housing.
In addition, portable communication apparatuses may be classified into rotation-type terminals and sliding-type terminals according to the mechanical opening and closing of the terminals. Rotation-type terminals have two housings coupled to each other so that one housing rotates to be opened or closed in relation to the other while facing each other. In the sliding-type terminals, two housings are coupled to each other so that one housing slides along a longitudinal direction to be opened or closed in relation to the other. These variously classified portable communication apparatuses can be easily understood by those skilled in the art.
As shown in FIGS. 1 to 5, a conventional sliding-type portable terminal 1 includes a main body 2 having a number of keypads 2a and a microphone device 2b and a sliding body 3 adapted to slide a distance corresponding to a half of the length of the main body 2 downward or upward open. The main body 2 generally has a 3×4 keypad array. The sliding body 3 has an auxiliary keypad made up of an array of a number of auxiliary keys, a speaker device 3a, and a display device 3b, all of which are positioned on the front surface thereof.
More particularly, the conventional siding-type portable terminal 1 includes a main body 2, a sliding body 3 adapted to slide a predetermined distance on the main body 2, guide means 4 positioned within the main body 2 and the sliding body 3 to guide the sliding body 3 on the main body 2, and at least one coil spring 5 positioned between the sliding body 3 and the main body 2 to provide an elastic force for the upward and downward sliding movement of the sliding body 3.
The main body 2 has a plate-shaped main plate 2c and the sliding body 3 has a plate-shaped sliding plate 3c as shown in FIGS. 3 and 4.
The guide means 4 include guide ribs 4a positioned on both sides of the plate-shaped sliding plate 3c and guide slots 4b positioned on the plate-shaped main plate 2c to be coupled to the guide ribs 4a. 
However, conventional sliding-type portable terminals, such as that shown in FIGS. 1 to 4 are problematic in that, when the sliding body is slid from the main body, the main body and the sliding body are arranged in a step-like manner (i.e., there is a difference in level between the main body and the sliding body). Therefore, a user cannot simultaneously press the keys on the main body and the auxiliary keys on the sliding body, making the terminal less user friendly. Furthermore, increased thickness of the terminals is an obstacle to manufacturing a slim terminal.
When the conventional sliding-type portable terminals are used to play games or other additional functions, the auxiliary keys on the sliding body may be erroneously operated while pressing the main body keys because of the level difference between the keys.